Refining copper-nickel matte



UNITED (STATES PATENT OFFICE.

NOAK v re'ron nrnmnr'rn, or CHRISTIANIA, NORWAY, m ROBERT LEE PEEK on OTTAWA, CANADA.

1,382,361.. No Drawing.

such as will enable others skilled in the art to which it appertains to make and use the same.

This invention relates particularly to the separation of copper and nickel by cementation of copper, from a solution containing the two metals, upon a metallic powder containing the samemetals, the cementation being carried out without heating the solution above the normal temperature. The process is of particular value in all cyclic processesv (such as electrolytic processes) where the same solution is used over and over again, at the normal temperature appropriate to the process, and where a certain amount of acidity has to be maintained in the solution It is well known that copper can be cemented upon nickel only under certain conditions, as, for instance, those set forth in United States patents to one ofus No. 805,969, and No. 1,128,313 and also, in United States patent granted to Langer and Langer No. 1,291,030. The processes referred to, however, prescribe heating of the solution, and necessitate subsequent cooling if the solution is to be subsequently used at a lower temperature, for example, as an electrol te, whereas the great expense involved in the heating and subsequent cooling operations is avoided by thePresent invention, wherein we are able to operate without such heating and subsequent cooling, and without such variations in the strength and concentration. of the solution, by evapora tion, as mun from such heating and coolmg operations. Particularly, moreover, as above noted, the process is of value in all cyclic operations where the same solution is used over an over agam, at a normal temperature for's'uch operations, and where a certainconcentration and amount of acidity has to be maintained in the solution.

Thus, we have found that if, in the cement- Specification of Letters Patent.

Patented June 21, 1921,

Application filed February 25,1e2o. Serial No. 361,275.

ing out of the copper, the solution is heated to, for instance, 70 C. or above the acid 1s, -m part at least, neutralized by the metalllc nickel employed, and the acidity must then be restored or readjusted in some way, to meet the, exigencies of the cyclic operat on. no also, if the solution is heated for the cementation, cooled, the water lost b evaporation must be replaced or readjuste to maintain proper concentration for the cyclic operation. This read ustment is entirely avoided or reduced to a minimum in our process, because the solution is not heated above the normal temperature, z. 6., the temperature at which it 1s produced or at which it is subsequently to be'used, or at which it is to be maintained in the cyclic operation.

In carrying out the process, We grind and roast the bessemerized copper-nickel matte,-

in much the usual manner, and subject it to treatment with dilute sulfuric acid so as to dissolve out the greater part of the copper present. A certain proportion of the roasted and leached matte is set aside for reduction to metallic owder and is afterward reduced by car on, hydrogen, carbon monoxid, hydrocarbons, or other reducing agent, preferably at the lowest temperature so that the metallic powder shall be in a correspondingly fine state of subdivision, appropriate to its subsequent use.

In the roasting leaching and reduction operations, it is of a vantage to sub 'ect the matte to a preliminary coarse grin ing for the roasted and leached matte to subsequent and subsequently finer grinding prior to the reduction. For

ordinary purposes, we consider the inding to 20 mesh or possibly 30 mesh, to e the most advantageous for roasting and leaching, and the subsequent rinding of the roasted and leached pow er to about 60 mesh, or p'ossibl 'even finer, prior to its reduction,in or er that the resulting metallic powder may be sufliciently fine to opthe metallic powder is to be employed will nevertheless proceed to some extent. and. a

solution. free of copper will always be proits duced even though the roasted and leached matte from which the metallic powder is erate to the best advantage in the subsequent f I reduced is not reground after leaching, although in such cases, the operation proceeds with a great deal less economy.

It will be noted that a portion only of the roasted and leached matte is set aside for reduction to metallic powder. The remainder may be dissolved and refined in any one of several ways; for instance, by direct solution in sulfuric acid, or by converting the matte into metal and dissolving the metal, to form a solutionor an electrolyte,

which may be purified from copper by treatment in the manner described below.

The amount of material set aside or withdrawn for reduction to metallic powder is preferably such that the powder will contain about two parts or more of nickel to every one part of copper contained in the remaining main body portion of the roasted and leached material, which is used to produce the copper-nickel solution to be treated therewith, so that, when the powder is used for the purification of the solution, there will be a large excess of nickel present.

To use the metallic powder in cementing out copper from the fairly neutral coppernickel solution above referred to,. it is brought into contact with said solution, at its normal temperature, in such amanner that a large excess of the metallic powder is used in the treatment of an initial portion of the solution and the cementation thusinitiated is repeated on fresh portions of the solution until no more copper will cement.

out without raising the temperature above the normal temperature of the solution. This method of using the metallic powder in the cementation operation is preferably carried out on the counter-current principle.

, for a complete precipitation of all the cop- As hereinbefore stated it is not necessary per to raise the temperature above a norma temperature of the solution (say 40 C. to C.) and, in some cases, it is of great advantage to dispense with the application of heat for other reasons than the cost thereof.

. In order to produce-copper freefrom nickel,

it'wouldbe necessary to applyheat, but we do not aim at such purification in the preswell as for other reasons,

- of the solution.

' "The metallic copper-nickel material con 'taining the copper cemented thereon, is

Therefore, for this reason, as we stop short of complete exhaustion of the-metallic powder, leavmg it in a condition wherein it still contains a large amount 'of metallic nickel Whichcouldfbe used for further, cementationit we desired to raise the temperature ent process.

'ven an oxidizing roast preferablyby mixing it with some'of the'original; copper I matte still-to be roasted, or even better, by jmi'x ing it withjpartly roasted matte, and

then proceeding with the roasting of the mixture. As hereinbefore stated, this metallic material has been ground so fine that it is not well suited forroasting and leach ing by itself, since if it were roasted alone,

of more or less: general application to the purification of nickel-copper sulfate solutions and electrolytes in order to free them from copper by cementation. It will be noted that an excess of the fine nickel-powzder is used manta the cementation oper- The process of the present invention is ation is carried out at the normal temperature of the solution, so that heating of the solution and subsequent cooling to the normal temperature is avoided. The normal temperature of the solution may be the tem perature at which the solution is produced, for example, from anickel-copper anode,and the purified nickel-sulfate solution, which is freed from copper without material change from the normal temperature, can then be returned to the electrolytic cell and made use of in the further carrying out of the electrolytic process, the entire. operation taking place without any material change in temperature from that of the normal temperature of the electrolytic operation. Thus, for example, where the electrolyte is to be maintained at" a temperature of about 55 G.- during the electrolytic operation, and

where an excess of acid is to be supplied 1 with the electrolyte and is present in the 1mpure nickel-copper sulfate solution produced from a nickel-copper anode, the cementation operation can be carried out without any material change in the normal temperature of the solution and the purified solution can be returned to the electrolytic cell without any considerable neutralization of its acidit or material change in its temhe process of the present 1nven perature. tion is therefore of special value when practised in conjunction with the separation of nickel and copper by electrolysis, as described in the prior'U. S. Patent No. 805,969, and in the process of the companion application of one of us Serial No. 358,968.

The nickel-sulfate electrolyte, containing an excess of sulfuric acid, may thus be introduced into the cathode compartment of an electrol tic cell and caused to flow throu h a filterlng diaphragm, .separatin the cat ode compartment from the ano e compartment, andthe impure nickel-copper solution, formed in the anode compartment from a nickel-copper anode, and containing an excess of sulfuric acid, can then be drawn off and subjected to purification by cementation, in the manner above described, and

without material change in .its temperature or any considerable change in its acidity, so that the purified nickel-sulfate solution can be returned to the cathode compartment andmade use of in the further carrying out of v the cyclic process. In its more comprehensive aspect, as above noted, the process of the present invention is of more eneral application; but the inventionis of particular value when combined in a cyclic'process in the manner above described. Accordingly, we wish to be understood as claiming the invention in its more comprehensive aspects, as well as in its more specific aspects when combined with a cyclic electrolytic process in the manner above described.

We claim: a

1. The method of purifying nickel-copper sulfate solutions from copperby cementa- I tion, which comprises bringing the solution into contact with an excess of finely divided nickel at a temperature below that of exhaustion of the nickel; substantially as de scribed.

2. The method of purifying nickel-copper sulfate solutions from copper by. cementation, which comprises bringing a nickelcopper sulfate solution containing an excess of free acid into contact withan excess of finely divided nickel at atemperature below that of neutralization of any considerable amount of the acid; substantially as described.

3. The processof separating copper from nickel, which comprises roastlng and leaching disintegrated bessemerized mckel-copper matte, reducing the roasted and leached material, and cementing out copper from a nickel-copper solution on an excess of such reduced material, without raisin the temerature of the solution substantially above its normal temperature; substantially as do scribed. I

4. The method ofurifying nickel-copper vsulfate electrolytes rom copper by cementation, which comprises bringing the electrolyte, while at a temperature appro riate for the subsequent electrolysis thereo into contact with an excess of finely divided nickel, without raising the temperature of the solution substantially above its normal temperature, and supplying the resulting nickel sulfate solution to the electrolytic process; substantiall as described.

5. The method 0 purifying nickel-copper sulfate electrol tes produced by. electrolysis from nicke popper, anodes, which comprises bringing the electrolyte, at substantially the normal temperature of its production, into contact with an excess of finely divided nickel and thereby removing the copper from the solution by cementation, and returning the purified nickel-sulfate solution without material change in temperature to the electrolytic cell.

6. The 'method of purifymg nickel-copper sulfate electrolytes from copper by cementation and of effecting the electro-deposition of nickel from the purified electrolyte, which comprises supplying the nickelsulfate electrolyte -t0 the cathode compartment of an electrolytic cell and causing the same to flow through a filter to the anode compartment, dissolving nickel and copper from a nickel-copper anode to form an impure nickel-copper sulfate electrolyte, bringing such electrolyte without material change in temperature, into contact with an excess of finely divided nickel and thereby freeing the solution from copper, and returning the purified electrolyte without material change in temperature to the cathode compartment of the cell. I

7. The method of purifyingv nickel-copper sulfate electrolytes and of separating nickel from the purified nickel-sulfate eleclyte to flow through said filter to the anode compartment, dissolving nickel and copper from a nickel-copper anode, drawing 01f the resulting nickel-copper sulfate solutlon with its excess acid and bringing the same into contact with an excess of finely divided nickel to free the solution from copper by cementation, and returning the purified elec trolyte to the cathode compartment-of the cell, the cementation operation being carried out without material change in temperature of the solution from the normal temperature of electrolysis; substantially as de scribed.

8. The processof separating copperfrom nickel, which comprises roastmg and leaching disintegrated bessemerized matte, reducing the roasted and leached material, and cementing out copper from a nickel-copper solution on such reduced material, using a large excess thereof, and repeating such cementation on fresh portlons of nickel-copper, solution until no more copper will cement out without raising the temperature ofthe solution substantially above normal; substantially as described.

9. The process of separating copper from nickel, whichcomprises roasting and leaching disintegrated bessemerized copper matte, reducing the roasted and leached material, and cementing out copper from anickel-copper solution on such reduced material, using a large excess thereof, and recopper neeaeer haustedmetallic 'material thus obtained;

substantially as described.

10. The process of separating copper from nickel, which comprises roasting and leaching disintegrated bessemerized copper matte,

' reducing the roasted and leached material,

and cementing out copper from a nickelcopper solution on such reduced material, using a large excess thereof, and repeating such cementation on fresh portions of nickelcopper solution until no more copper will cement out without raising-the temperature of the solution substantially above normal, then mixing the but partly exhausted metallic material with further amounts of matte and roasting the mixture; substantially as described.

11. The process of separating copper from nickel, which comprises roasting and leaching disintegrated bessemerized copper matte, regrinding a portion thereof to a fineness greater than is favorable for roasting and leaching, reducing'the reground material, and cementing out copper from nickelcopper solution on such reduced material without raising the temperature of the solution substantially above the normal temperature'; substantially as described.

12. The rocess of separating copper from nickel, wh ch comprises roasting and leaching disintegrated bessemerized nickel-copper matte, regrinding a portion of the roasted and leached material to a fineness greater than is favorable for roasting and leaching, reducing the same, and cementing out copper from a nickel-copper solution on such reduced material, using a large excess thereof,

repeating such cementation on fresh portions of nlckel-copper solution until no more copper will cement out without raising the temperature of the solution substantially above the normal, mixing the but partly exhausted metallic material thus obtained with partly roasted matte and roasting the mixture; substantially as described.

13. The method of treating a nickel-copper powder produced by cementation of copper upon nickel without complete exhaustion of the nickel, which comprises admixing such powder with ortions of fresh or partly roasted matte, an to a roasting operation; substantially as described.

14a The method of separating copper from nickel, which comprises bringing a nickelcopper sulfate solution into contact with an excess of finely divided nickel at a temperature below that of exhaustion of the nickel and thereby producing a product containing a smaller amount of nickel and an increased amount of copper, admixing such product with fresh or partly roasted or re ,sted

matte, and subjecting the mixture to a further roasting operation.

In testimony whereof we afix our signatures. V I

NOAK VTCTUE HYBTNETTE. ROBERT LEE PEEK.

subjecting the mlxture 

